Cable type condenser



June 2, 1931. E. D. EBY

CABLE TYPE coNDENsm Filed Jan. 18, 1930 Figi.

11m/enter` I Eugene D. Eby. @car/ H is Attorney.

Patented June 2, 1931 UNITED s'lza'ras' PATENT OFFICE EUGENE D. EBY, FPITTSFIELRVHASSACHUSETTS, ASSIGNOB T0 GENERAL ELECTRIC COMPANY, ACORPORATION 0F NEW YORK l CABLE lTYPE CONDENSEB l Application ledJanuary 1B, 1930. Serial No. 491,880.y

My invention relatesto condensers or capacitors ofthe cable type such asthat dis-rl closed in my United States Patent No. 1,731,890, issuedOctober 15,1929. Thist pe 5 of condenser utilizes a metal sheathed ca lethe inner conductor and the metal sheath ci the cableforming theconductive elements of the condenser and being insulated from each otherby the cable insulation which- In the con- 410 forms the 4condenserdielectric.

denser disclosed in the above, the cable is in the 'atent referred to rmof a loop, the

two ends' of the inner conductor of the cable being brought togetherwithin an insulating bushing and being connected to a commonv terminal.If this terminal is connected to va source of electrical ener such as aconductor of a power transmission circuit, the inner conductor of thecable isv maintained at the potential of the source and a current may betaken from the cablesheath through the capacity between the sheath'andthe inner conductor of the cable. The main current iiowing in thetransmission line or other source to which the condenser is connecteddoes not, however, iiow through the cable so that it is not possible touse the cable in combination with a current transformer. The generalobject of the resent invention is to provide an improve cable typecendenser of such construction and arrangement as to permit it to beused eectively in combination with a current transformer.

Other objects and advantages will appear from the following descriptiontaken in connection with the accompanying drawings in which Fi 1 is aview in elevation of a combined cab e type condenser and currenttransformer constructed in accordance with the upper en rtion of thecondenser, and Fig. 3 is an e arged sectional view on the line 43 3 ofFig. 1. I

Like re erences indicate similar parts in both figures of the drawings.

The particular form of the invention shown in-the drawings includes ametal sheathed cable 10 formed into 'a depending loop and supported andheld in shape by a frame 11 which is secured to the lower end of ahollow tendiner through the baseof the cap 18. The

inventiox Fig. 2 is a sectional view of the bushing. 12. Both ends ofthe outer metal sheath 8 of the cable 10 are connected by sealed joints13 to the bottom of a casing 14 depending from the lower end of thebushing 12. The cable 10 is shown as having two conductors 15 and 16insidethe sheath, the

two conductors being separated from each other and from the sheath byinsulation 9. It will be apparent, however, that a different number oconductors may be used if desired. The conductor 16 is formed of aplurality of strands concentrically surrounding theinsulated centralconductor 15 and sepaated from the outer sheath by insulation A hollowmetal cap 18 is secured to the top of the bushing 12 by screwing it to ametal ring 19 cemented around the upper edge of the bushing, a gasketbeing interosed between the cup and ring to prevent eakaoe of insulatingoil which preferably fills the bushing and cap and extends down into anylspaces in the casing 14 .and the cable 10.

The metal sheath 8 is removed from the cable 10 above the seals 13 butboth ends of both of the conductors 15 and 16 extend up through thebushing 12 as indicated in Fig. 2, the ends of the central conductor 15exends o? the conductor 16 are connected electrically and mechanically,as by soldering, to the lower ends of two metal tubes `20 and 21 whichsurround the ends of the central conductor 15 and extend throu h thebase of the cap 18. The upper ends o the tubes 20 and 21 are providedwith threaded nuts 22 and' 23 respectively which have shoulders restingon the base of the ca l 18 and thus help to support the cable 10. e nut23 on the tube 21 1s of insulating material t9 insulate the tube 21 fromthe cap 18 and the other tube 20. The end of the central conductor 15which is surrounded by the tube 21 is connected to a terminal 24extending throughvthe wall of the cap 18. The tube 21 is connected by aconnector 25' to the end of the'central conductor 15 which issurroundedby the tube 20. The tube 20 is connected throu h the nut 22 to a secondterminal 26 exten ing through the 100 wall ofthe cap 18. Thus the twoconductors 15 and 16 form two loops within the sheath ot the cable 10and are connected in series between the terminals 24 and 26. .The outermetal sheath 8 is insulated from the conductors 15 and 16 by theinsulation 17 Kand these parts therefore constitute the elements cfacondenser.

The condenser is adapted to be connected through its terminals 24C and26 in ser-ies with one side of' an electrical circuit 27 such as a powertransmission line as shown in 1. When so connected, the conductors 15and 16 of the cable 10 will be maintained at the po` tential of thecircuit 27 and current may be taken from the sheath 8 of the cablethrough the capacity between the sheathand the cable conductor 16. It isalso obvious that the main current in the circuit 27 will flow throughthe conductors 15 and 16 in series which may therefore serve as theprimary turns of a current'transformer 28 surrounding the cable 10 asshown in Fig. 1. It is well'known that a current transformer having asingle turn primary does .not usually have very great accuracy and thatits accuracy may be improved by increasing the number of its primaryturns. The construction which has been described has the advantage ofproviding two primary turns for the transformer 28 and v it will beapparent that a greater number of primary turns may be provided ifdesired by using a cable having an appropriate number of conductors.

rlhe invention has been explained. by describing and illustrating aparticular embodiment thereof but it will be apparent that vchanges maybe made without departing from the spirit of the invention or the scopeof the appended claims.

at I claim as new and desire to secure by Letters Patent of the UnitedStates is :v

1. A combined condenser and current transformer including an insulatingbush- Yto ing, a cable having a conductor and a metal sheath surroundingand insulated from the conductor, said cable being in the forni of aloop with its two ends extending into said bushing, the two ends of saidsheath beingA sealed t'o one. end of said bushing, a pair of terminalsnear the other end of said bushing,

said cable conductor being connected between said terminals, and acurrent transformer surrounding the looped part of said cable.

2. A combined condenser and current transformer including an insulatingbushing, a cable having a plurality of conductors and a metalsheathsurrounding andl insulated from said conductors, said cable beingin thev Isaid cable conductor may be connected in series with anelect'rical circuit to serve as the primary circut for a currenttransformer surrounding the looped part of said cable.

4.-. A condenser including an' insulating bushing, a cable having aplurality of conductors and a metal sheath surrounding and insulatedfrom said conductors, said cable so j being in the form of a loop withVits t'wo ends extending into said bushing, the 'two ends of said sheathbeing sealed to one end of said bushing, and a pair of terminals nearthe other end of said bushing, and said cablev conductors beingconnected in series between said terminals. y

In witness whereof, I have hereunto set my hand this 13th day ofJanuary, 1930./

EUGENE D. EBY.

